Java :如何在运行时修改config.properties？

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

public class ConfigModifier {
    public static void main(String[] args) {
        Properties props = new Properties();
        FileInputStream in = null;
        FileOutputStream out = null;
        
        try {
            // 加载配置文件
            in = new FileInputStream("config.properties");
            props.load(in);
            
            // 修改配置
            props.setProperty("key", "value");
            
            // 保存修改后的配置文件
            out = new FileOutputStream("config.properties");
            props.store(out, null);
            
            System.out.println("配置文件修改成功！");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭流
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

key1=value1
key2=value2